Raw clay material-based modified carbon paste electrodes for sensitive heavy metal detection in drinking water

A new electrode based on carbon paste (CP) modified with natural clay was used for heavy metals detection. The investigation of the raw clay material (X-ray diffraction, infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermal analysis and particle size distribution) revealed different morpho-structural properties of the natural material. The electrochemical behaviour of the modified carbon paste electrode and its ability to detect heavy metals (Zn2+, Cd2+, and Cu2+) was studied by different electrochemical techniques like cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave anodic stripping voltammetry (SWASV). Both electrochemical and analytical parameters of the investigated modified electrode recommend them as stable, sensitive and reproducible sensors for individual heavy metals detection.